A174658 Balanced ternary numbers with equal count of negative trits and positive trits.

0, 2, 6, 8, 16, 18, 20, 24, 26, 32, 46, 48, 52, 54, 56, 60, 62, 70, 72, 74, 78, 80, 86, 96, 98, 104, 130, 136, 138, 142, 144, 146, 154, 156, 160, 162, 164, 168, 170, 178, 180, 182, 186, 188, 194, 208, 210, 214, 216, 218, 222, 224, 232, 234, 236, 240, 242, 248, 258

Offset: 1

Author

Daniel Forgues, Mar 26 2010

Keywords

• base
• nonn

Comments

Numbers for which the sum of trits is zero.

Links

• Daniel Forgues, Table of n, a(n) for n=1..14309

Crossrefs

Cf. A174657, A174659, A065363, A140267, A257869.

Programs

Mathematica

(* First run the program for A065363 to define balTernDigits *) A174658 = Select[Range[0, 299], Plus@@balTernDigits[#] == 0 &] (* Alonso del Arte, Feb 24 2011 *)

Python

def a(n):
    s=0
    x=0
    while n>0:
        x=n%3
        n //= 3
        if x==2:
            x=-1
            n+=1
        s+=x
    return s
print([n for n in range(301) if a(n)==0]) # Indranil Ghosh, Jun 07 2017